"The way of the LORD is strength to the upright: but destruction shall be to the workers of iniquity." -Proverbs 10:29, KJV.

Those who live in sin (living for sin, not just sinning as we're all sinners) will face destruction from their sin. However, those who are trying to live their lives right will be given strength by following God's way. For example, when we are greedy to the point that we won't give anyone anything, it tends to eat us up inside, whether we realize it or not. However, if we give selflessly, then we have this great almost release that fills our soul. Even the unsaved can experience this principle (hence why charities exist), but the real benefit is to those who are no longer under the power of sin and can stay in the way of the LORD through prayer and Bible reading.